Aquatic device

ABSTRACT

An aquatic device ( 10 ) for providing manoeuvrability to a user ( 11 ) moving in water. The aquatic device ( 10 ) may be propelled through the water in any appropriate way, such as by being towed through the water or propelled through the water by the user ( 11 ). The aquatic device ( 10 ) comprises a handle means ( 20 ) adapted to be grasped by the user ( 11 ) with arms extending forwardly, and two fins ( 21, 22 ) movable one with respect of one to the other to manoeuvre the aquatic device. The aquatic device ( 10 ) can be manoeuvred through movement of the fins ( 21, 22 ) to provide directional control or variation to the orientation of the aquatic device. The directional control may include both steering and depth control. The handle means ( 20 ) are operably connected to the two fins ( 21, 22 ) whereby the user can manually control movement of the fins one with respect to the other.

FIELD OF THE INVENTION

This invention relates to an aquatic device, and more particularly to an aquatic device for providing manoeuvrability to a user moving in water.

BACKGROUND OF THE INVENTION

There have been various proposals for manoeuvring a person through a body of water. The proposals typically involve devices for propelling a user through a body of water in a manner which allows the user to travel either along the water surface or under water. Such devices have recreational applications and are also particularly suitable for underwater pursuits such as diving and snorkelling.

One known type of such device is disclosed in U.S. Pat. No. 5,558,551 which involves a planar member adapted to be towed behind a boat by way of a tow line to which the planar member is attached. The planar member incorporates handle apertures by means of which a user can grasp the planar member to be towed along. The planar member can be articulated by the user to provide some limited depth and steering control within the water while being towed behind the boat.

While articulation of the planar member does provide some steering and depth control, there can be a significant lag between articulation of the planar member and a resultant directional change in the movement of the user. Accordingly, there can be a lack of responsiveness and subtle changes in direction can be difficult to achieve. Further, it may be necessary for the user to rotate his or her body in order to achieve articulation of the planar member for directional control.

An aquatic device which is propelled by a user (rather than being towed) is a swimming kick board commonly used to improve the kicking action of swimmers. Such an aquatic device offers limited direction control through tilting of the board and is generally not suitable for use underwater.

It is against this background that the present invention has been developed.

The above discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge in Australia as at the priority date of the application.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided an aquatic device comprising handle means adapted to be grasped by a user, and two control elements moveable one with respect to the other to manoeuvre the aquatic device.

The aquatic device may be manoeuvred through movement of the control devices to provide directional control or variation to the orientation of the device (and hence to the user holding the device). The directional control may include both steering and depth control (including at least descension and ascension).

Preferably, the control elements comprise fins.

Each control element may comprise a leading end, a trailing end, and upper and lower control surfaces therebetween. The upper and lower control surfaces may taper inwardly with respect to each other in the direction towards the trailing end. The leading end may be profiled to facilitate movement through the water. The leading end may, for example, present a rounded profile or alternatively be of angular configuration incorporating a leading edge.

Each control element may be configured to guide water flow along the control surfaces. Specifically, each control element may comprise protrusions extending from either or both of the upper and lower control surfaces. The protrusions may comprise an inner rib extending between the leading end and the trailing end of each control element. The protrusions may further comprise an outer rib extending between the leading end and the trailing end of each control element.

The outer rib is preferably located at an outer side edge of the control element. The ribs outer rib may be arcuate in cross-sectional profile. Further, the outer rib may be configured to taper inwardly in the forward direction and merge with the leading end of the control element.

The inner and outer ribs provide flow control elements for guiding oncoming water with respect to the upper and lower control surfaces, impeding spillage of water sidewardly prior to reaching the trailing end. Further, the protrusions which provide the outer ribs may function as a safety edge along the at the outer side edges of the control elements

Preferably, the handle means are operably connected to the two fins whereby the user can manually control movement of the control elements one with respect to the other.

Preferably, the control elements are pivotally moveable with respect to each other.

Preferably, the control elements are movable about a common pivot axis.

Preferably, the common axis is generally transverse to the direction of travel.

Preferably, the pivot axis is generally horizontal when the aquatic device is travelling in a generally horizontal straight line direction.

Preferably, the handle means comprises two handles each connected to a respective one of the control elements.

In one arrangement, the two control elements may be disposed adjacent each other and the two handles located laterally outwardly thereof. In other arrangement, the two handles may be disposed adjacent each other and the two control elements located laterally outwardly thereof.

Preferably, the relative positions of the handles with respect to the control elements are selectively variable. In other words, the configuration of the aquatic device can be changed between the arrangement in which the two control elements are disposed adjacent each other and the two handles located laterally outwardly thereof, and the arrangement in which the two handles are disposed adjacent each other and the two control elements located laterally outwardly thereof.

Preferably, the aquatic device further comprises an axle wherein the control elements and the respective handles connected thereto are rotatably supported on the axle. In one arrangement, the axle may provide a spindle upon which the control elements and the respective handles pivot. In another arrangement, the axle may provide a spindle pivotally interconnecting the control elements and the respective handles

The control elements and the handles may be removable from the axle. This may allow for disassembly for ease of transport and storage. Further is may facilitate the selective variation of the relative positions of the handles with respect to the control elements.

The aquatic device according to the invention may be propelled through the water in any appropriate way. In one arrangement, the aquatic device may be adapted to be towed through the water. In another arrangement, the aquatic device may be propelled through the water by the user. In still another arrangement, the aquatic device may have an on-board propulsion system.

Where the aquatic device is adapted to be towed through the water by way of a tow line, the device preferably has a connection means for attachment to the tow line. The connection means preferably provides for detachable connection to the tow line.

Preferably, the connection means is associated with the axle. In one arrangement, the connection means may comprise a bridle having sections extending from each end of the axle. In another arrangement, the connection means may comprise a coupling on the axle, preferably centrally located such there is a respective control element and handle to each side thereof. The aquatic device may be fitted with both connection arrangements in order to provide the user with a choice.

According to a further aspect of the invention there is provided an aquatic device for towing a user through a body of water, the aquatic device comprising handle means adapted to be grasped by the user, and two control elements moveable one with respect to the other for directional control of the device.

According to a still further aspect of the invention there is provided an aquatic device comprising handle means adapted to be grasped by a user to apply propulsion thereto, and two control elements moveable one with respect to the other for manoeuvring the aquatic device while being propelled by the user, the handle means being operably connected to the two control elements whereby the user can manually control movement of the control elements one with respect to the other.

According to a still further aspect of the invention there is provided a swimming aid comprising handle means adapted to be grasped by a user, and two control elements moveable one with respect to the other to manoeuvre the swimming aid, the handle means being operably connected to the two control elements whereby the user can manually control movement of the control elements one with respect to the other.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by reference to the following description of several specific embodiments thereof as shown in the accompanying drawings in which:

FIG. 1 is a schematic perspective view of an aquatic device according to a first embodiment in use;

FIG. 2 is a further schematic perspective view of the aquatic device in use;

FIG. 3 is a schematic perspective view of the aquatic device in a disassembled condition;

FIG. 4 is a schematic perspective view of the aquatic device assembled in a first configuration and having a bridle connection to a tow line;

FIG. 5 is a schematic perspective view of the aquatic device assembled in a second configuration and having the bridle connection to the tow line;

FIG. 6 is a schematic perspective view of the aquatic device in the configuration of FIG. 5 but having a central connection to the tow line;

FIG. 7 is a schematic perspective view illustrating the aquatic device in use towing a user, with the aquatic device being in a condition to descend;

FIG. 8 is a schematic perspective view illustrating the aquatic device in use towing a user, with the aquatic device being in a condition to ascend;

FIG. 9 is a schematic perspective view illustrating the aquatic device in use towing a user, with the aquatic device being in a condition to rotate anti-clockwise or alternatively perform a left turn;

FIG. 10 is a view similar to FIG. 9, with exception that the aquatic device is in a condition to rotate clockwise or alternatively perform a right turn;

FIG. 11 is a front view showing rotation of the aquatic device when in the condition shown in FIG. 9;

FIG. 12 is a front view showing rotation of the aquatic device when in the condition shown in FIG. 10;

FIG. 13 is a schematic perspective view of an aquatic device according to a second embodiment in use;

FIG. 14 is a view similar to FIG. 13 except that the aquatic device is shown in a condition to descend;

FIG. 15 is a further schematic perspective view of the aquatic device according to the second embodiment in use;

FIG. 16 is a schematic perspective view of an aquatic device according to a third embodiment;

FIG. 17 is a perspective view of an aquatic device according to a fourth embodiment;

FIG. 18 is a side view of the aquatic device according to the fourth embodiment;

FIG. 19 is front view of the aquatic device according to according to the fourth embodiment;

FIG. 20 is perspective of the aquatic device according to according to the fourth embodiment, with one of the fins rotated;

FIG. 21 is a perspective view of the aquatic device according to the fourth embodiment;

FIG. 22 is a perspective view of the aquatic device according to the fourth embodiment in use;

FIG. 23 is a cross-sectional view of the aquatic device according to the fourth embodiment;

FIG. 24 is a perspective view of a portion of the aquatic device according to the fourth embodiment providing one of the handles;

FIG. 25 is a cross-sectional view of the central coupling portion of the aquatic device according to the fourth embodiment;

FIG. 26 is an exploded view of the central coupling portion;

FIG. 27 is a perspective view of an element forming part of the central coupling portion;

FIG. 28 is a side view of the element of FIG. 27;

FIG. 29 is an end view of the element of FIG. 27

FIG. 30 is a perspective view of the aquatic device according to a fifth embodiment;

FIG. 31 is a perspective view from the front of a fin of the aquatic device according to the fifth embodiment;

FIG. 32 is a perspective view from the rear of the fin of FIG. 31; and

FIG. 33 is a plan view of the fin of FIG. 31.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1 to 12 of the drawings, there is shown an aquatic device 10 according to the first embodiment for towing a user 11 through a body of water 13. The aquatic device 10 is adapted to be towed behind a boat 15 by way of a tow line 17, and the user 11 may travel on or under the water.

The aquatic device 10 comprises handle means 20 adapted to be grasped by the user 11 with arms extending forwardly, and two fins 21, 22 pivotally moveable with respect to each other.

The aquatic device 10 further comprises an axle 23 onto which the handle means 20 and the fins 21, 22 are pivotally mounted. In the arrangement shown the axle 23 is tubular, comprising a rigid tube of any appropriate material such as aluminium.

The handle means 20 comprises two handles 24 each connected to a respective one of the fins 21, 22. With this arrangement, the combination of each handle 24 and its respective fin 21, 22 comprises a control unit 25. The control units are rotatably mounted on the axle 23.

Each handle 24 comprises a tubular shaft 26 and a hand grip 27 provided on the outer side of the shaft. The tubular shaft 26 is rotatably mounted on the axle 23. The hand grip 27 is configured to offer a comfortable grip for the user.

Each fin 21, 22 comprises a fin body 28 having an upper control surface 29, a lower control surface 30, a leading end 31 and trailing end 32. The upper and lower control surfaces 29, 30 taper towards each other in the direction towards the trailing end 32. The fin body 28 is of hollow construction with an open interior 34 for ingress of water to reduce buoyancy effects. In the arrangement shown, the leading end 31 is configured to present a rounded profile to oncoming water as the aquatic device 10 is propelled through the water.

Each fin 21, 22 incorporates a sleeve portion 35 having a hole 36 which extends crosswise through the body 28 adjacent the leading end 31 and which is co-axial with the tubular shaft 26. With this arrangement, the fins 21, 22 can be rotatably mounted on the axle 23 by virtue of the axle being received within the hole 36.

The tubular shaft 26 of each handle 24 is connected to the respective fin 21, 22 such that rotation of the handle 24 causes rotation of the respective fin.

The control units 25 can be positioned on the axle 23 selectively in either one of two arrangements. In the first arrangement, which is best seen in FIG. 4, the control units 25 are oriented such that the two fins 21, 22 are disposed adjacent each other and the two handles 24 are located laterally outwardly thereof adjacent the ends of the axle 23. In the second arrangement, which is best seen in FIG. 5, the control units 25 are oriented such that the two handles 24 are disposed adjacent each other and the two fins 21, 22 located laterally outwardly thereof adjacent the ends of the axle 23. The first arrangement is particularly suitable for larger children and adults who may have a preference for a wider grip on the aquatic device 10 as it is likely to be more comfortable. The second arrangement is particularly suitable for small children whose grip might not be able to span the distance between the handles 24 when they are not disposed adjacent each other.

A spacer 37 is provided on the axle 23 between the two control units 25. End fittings 41 are provided on the axles 23 in order to retain the control units 25 in position thereon. The end fittings 41 are removable to facilitate disassembly of the aquatic device 10 or to alter the configuration of the control units 25 on the axles 23. Spacers 42 are provided between each end fitting 41 and the adjacent control unit 25.

A bridle 43 is provided on the axle 23 for attachment to the tow line 17. The bridle 43 has two bridle sections 45 which extend from the ends of the axle 23 to a common coupling 47 releasably attachable to the tow line 17. In the arrangement shown, the bridle 43 comprises a loop 49 in the form of a length of rope or cable extending through the tubular axle 23 and connected at its ends to the common coupling 47. The loop 49 may be constrained in any appropriate way to prevent it from sliding within the axle 23.

The central spacer 37 may incorporate a coupling 51 providing an attachment point to which the tow line 17 can be connected, if desired, in order to offer an alternative connection to the tow line 17 to that provided by the bridle 43. Such an arrangement is illustrated in FIG. 6. If the coupling 51 is used to provide the connection to the tow line 37, the bridle 43 can be removed from the axle 23.

Operation of the aquatic device 10 according to the first embodiment will now be described. The aquatic device 10 is coupled to the tow line 17 in the manner described so that it can be towed behind the boat 15 with the user 11 holding the handles 24 at the hand grips 27 with arms extending forwardly. In this way, the user 11 can be towed behind the aquatic device 10 as it is pulled through the water 13 by the boat 15.

The user 11 is able to manoeuvre the aquatic device 10 by turning the handles 24 to move the fins 21, 22. If the user wishes to travel in a straight-line direction, the two fins 21, 22 are positioned in alignment with each other and also in general alignment with the direction of travel, as illustrated in FIG. 1. Where the user 11 wishes to descend (for example to perform a dive), the user 11 merely rotates both fins 21, 22 upwardly, as shown in FIG. 7. Similarly, where the user 11 wishes to ascend, he or she merely rotates both fins 21, 22 downwardly as illustrated in FIG. 8.

The user 11 may in certain circumstance vary his or her orientation, and in other circumstances possibly achieve some steering control, by rotating one fin 21, 22 relative to the other, as illustrated in FIGS. 9 and 10. In FIG. 9, the right fin 22 is shown rotated downwardly and the left fin 21 is shown rotated upwardly, thereby causing the aquatic device 10 to either rotate in an anti-clockwise direction (with respect to the direction of travel) as indicated by arrow 61 or alternatively perform a left turn (with respect to the direction of travel) as indicated by arrow 62. In FIG. 10, the left fin 21 is shown rotated downwardly and the right fin 22 is shown rotated upwardly, thereby causing the aquatic device 10 to either rotate in a clockwise direction (with respect to the direction of travel) as indicated by arrow 63 or alternatively perform a right turn (with respect to the direction of travel) as indicated by arrow 64. FIG. 11 illustrates schematically rotation of the aquatic device 10 and the user 11 when the fins 21, 22 are in the condition shown in FIG. 9. Similarly, FIG. 12 illustrates schematically rotation of the aquatic device 10 and the user 11 when the fins 21, 22 are in the condition shown in FIG. 10.

Whether the aquatic device rotates or performs a turn (or indeed perhaps manoeuvres in a manner involving both rotation and a turn) may depend on various factors including the depth at which the device is operating and the speed at which it is being towed.

There may be provision for tethering the aquatic device 10 to the user 11 to allow the user to temporarily release the handles 24 without losing access to the aquatic device. This may be particularly suitable in circumstances where the user has a need to use his or her hands for other purposes, such as for collecting materials or inspecting underwater objects. Such tethering can be achieved in any suitable way, such a with as flexible tether line connected between the user and the aquatic device. With such an arrangement, the user could release the aquatic device 10 to free his or her hands for other purposes and could subsequently retrieve the aquatic device by hauling in the tether line.

The aquatic device 10 may also have provision for fitting various accessory devices, such as an underwater lighting system and holders for equipment (such as tools and other devices). Lights could, for example, be fitted onto the fins 21, 22.

In the first embodiment, the aquatic device 10 is configured to be propelled by being towed through the water. Referring now to FIGS. 13 to 15, there is shown an aquatic device 10 according to a second embodiment which is adapted to be propelled by the user 11. The aquatic device 10 according to the second embodiment can merely be the aquatic device 10 according to the first embodiment but configured differently. The ability to configure the aquatic device 10 in such different ways is particularly advantageous as it provides various options regarding the manner in which the aquatic device can be used. In the arrangement shown, the different configuration involves removal of the bridle 43, as there is no need for a connection to a tow line

In this second embodiment, the aquatic device 10 is propelled by the user 11. In the arrangement shown, the user 11 is wearing flippers 12 to generate propulsion in the water. The user 11 in effect pushes the aquatic device 10 through the water, using it for manoeuvring purposes. The user 11 is able to achieve depth and steering control by operating the aquatic device to manipulate the fins 21, 22 in a manner similar to that described in relation to the first embodiment. Because the aquatic device 10 is not being towed, it is likely that the user would be able to turn through a full circle should that be desired. When using the aquatic device according to this embodiment, the user may find it necessary to wear a weight-belt in order to overcome buoyancy effects.

Referring now to FIG. 16, there is shown an aquatic device according to a third embodiment. This third embodiment is similar in many respects to the second embodiment and so like reference numerals are used to denote corresponding parts. In this embodiment, the fins 21, 22 are of a closed construction to exclude the ingress of water. With this construction, the fins 21, 22 can be either buoyant or non-buoyant, according to the material or materials from which they are constructed. Further, the leading end 31 is configured to present a leading edge 31 a to the oncoming water as the aquatic device is moved through the water.

Referring to FIGS. 17 to 29 of the drawings, there is shown an aquatic device 140 according to a fourth embodiment. In the arrangement shown, the aquatic device 140 is intended to be propelled by a user 190, as shown in FIG. 22. However, it should be understood that the aquatic device 140 could be adapted to be towed in the manner of the first embodiment.

The aquatic device 140 comprises handle means 141 adapted to be grasped by the user 190 with arms extending forwardly, and two control elements such as fins 144, 145 pivotally moveable with respect to each other.

The handle means 141 comprises two handles 142 interconnected by a rotatable coupling 143.

The coupling 143 provides an axle 146 onto which the handles 142 are pivotally mounted.

Each fin 144, 145 comprises a fin body 152 having an upper control surface 156, a lower control surface 160, a leading end 164, a trailing end 168, an outer side edge 165 and an inner side edge 167. The upper and lower control surfaces 156 and 158 taper towards each other in the direction towards the trailing end 168. In the arrangement shown, the leading ends 164 are hydrodynamically configured to present an edge profile to oncoming water as the aquatic device 140 is propelled through the water. The edge profile at the leading ends 164 is rounded in the embodiment.

Referring to FIG. 23, each fin 144, 145 incorporates a sleeve portion 172 located at its leading inner corner for mounting of the fins 144, 155 onto the handle means 141 via a male portion 174 located at an end of each handle 142. The fins 144, 145 are releasably attached to the handle means 141 so they can be removed to facilitate disassembly of the aquatic device 140 or to alter the configuration of the aquatic device by locating different type of fins 144, 145.

With this arrangement, the combination of each handle 142 and its respective fin 144, 145 comprises a control unit 180. As shown in FIG. 24, each handle 142 comprises a hand grip 182 which is configured to offer a comfortable grip for the user.

Fins 144 and 145 are configured with rounded corners 184 and rounded leading ends 160 and trailing ends 164 (see FIG. 18) to provide safety edges that are not sharp and thus not likely to harm the user 190 or persons close to the user while the aquatic device is being used.

As shown in FIGS. 17 to 20, the fins 144, 145 are configured to guide water along the control surfaces 156, 160. Specifically, each fin 144, 145 comprises protrusions 186, 188 that protrude from the upper and lower control surfaces 156, 160. Protrusions 186 each comprise an inner rib 187 extending from adjacent the sleeve portion 172 to the trailing end 168, inwardly of the inner side edge 167. Protrusions 188 each comprise an outer rib 189 at the outer side edge 165, extending from the leading end 164 to the trailing end 168. The ribs 189 are arcuate in cross-sectional profile, as shown in FIG. 19. Further, the ribs 189 are configured to taper inwardly in the forward direction and merge with the leading end 160 of the fin, as best seen in FIGS. 20 and 23.

The ribs 187, 189 provide flow control elements for guiding oncoming water over the upper and lower control surfaces 156, 160 of the fins 144,145, impeding spillage of water sidewardly prior to reaching the trailing end 168 of the fins.

All edges of protrusions 186 and 188 are rounded to avoid injury of the user or persons close to the user while the aquatic device is being used. Further, the protrusions 188 which provide the outer ribs 189 function as a safety edge along the at the outer side edges 165 of the fins.

The control units 180 are rotatably mounted on the axle 146 and for this purpose the opposite end of the handle means 141 comprises a sleeve portion 176 (see FIG. 24) for mounting the handle means 141 rotatably onto the axle 146 via male portions 206 located at each end of axle 146 (see FIG. 26).

FIGS. 25 to 29 show the axle 146 and the elements that comprise it. In the arrangement shown, the axle 146 is tubular and comprises a centre element 194 having an irregular outer surface 148 and two ends 150 onto which the handle means 141 are attached.

The rotatable coupling 143 which provides the axle 146 comprises two inner coupling portions 202 interconnected for rotational one relative to the other by a hinge pin 198. An outer coupling sleeve surrounds the two coupling portions and serves to retain the assembly together.

Each inner coupling portion 202 comprises a shank section 204 at one end, a spigot section 206 at the other end, and an intermediate section 207 comprising a boss and incorporates a gripping formation 216. The shank section 204 incorporates a bore 205 into which the hinge pin 198 is rotatably received.

The coupling sleeve 196 is of resilient construction to permit relative rotational movement (albeit to a limited extent) between the handles 142. In the illustrated arrangement, the coupling sleeve is formed of a resiliently flexible plastics material and has lateral ribbing on the outer surface thereof to enhance its flexibility.

The ends of the coupling sleeve 196 are received on the bosses 214 of the inner coupling portions 202 and clampingly retained thereon by clamping rings 218.

With this arrangement, the coupling sleeve 196 retain the assembly of the two inner coupling portions 202 together with the hinge pin 198 extending therebetween, while allowing limited pivotal movement of one inner coupling portion 202 relative to the other (thereby accommodating relative rotational movement between the two handles 142 and the fins connected thereto). Further the outer coupling sleeve 196 seals the assembly against the ingress of water and foreign matter such as sand and grit.

Each handle 142 comprises a body 171 having a central portion 173 defining the hand grip 182. The handle body 171 has an outer end configured as a spigot 174 for connection to the sleeve portion 172 of the respective fin, and an inner end configured as a socket 176 to receive the spigot section 206 of one of the inner coupling portions 202. A locking mechanism 208 is provided for retaining the spigot section 206 in the socket 176

In this fourth embodiment, the aquatic device 141 is propelled by the user 190 (see FIG. 22) thus acting as a swimming aid. In the arrangement shown, the user 190 is wearing flippers 192 to generate propulsion in the water. The user 190 in effect pushes the aquatic device 190 through the water, using it for manoeuvring purposes. The user 190 is able to achieve depth and steering control by operating the aquatic device to manipulate the fins 144, 145 in a manner similar to that described in relation to the first embodiment. If the aquatic device 190 is not being towed, it is likely that the user would be able to turn through a full circle should that be desired.

Referring now to FIGS. 31 to 33, there is shown an aquatic device according to a fifth embodiment. The aquatic device according to this fifth embodiment is similar in many respects to the fourth embodiment and so corresponding reference numerals are used to identify corresponding parts. In this fifth embodiment, each rib 189 is configured to extend along the outer side edge 165 and at least partly along the leading end 160 of the fin body 152 to ultimately merge therewith. Each rib 189 is configured to ensure that the hydrodynamics of the respective fin are not compromised.

From the foregoing, it is evident that the present embodiments each provide a simple yet highly effect aquatic device which can be easily operated by a user in order to provide manoeuvrability through the water.

It should be appreciated that the scope of the invention is not limited to the scope of the embodiments described. For example, in the first embodiment described, the aquatic device 10 is adapted to be towed behind a boat. Other towing arrangements may, of course, be utilised; for example, an overhead cable towing system, a land-based towing system or simply some other person manually pulling the aquatic device along.

Further, in an alternative arrangement, the aquatic device may incorporate an on-board propulsion system.

Throughout the specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. 

1. An aquatic device comprising handle means adapted to be grasped by a user, and two control elements moveable one with respect to the other to manoeuvre the aquatic device.
 2. An aquatic device according to claim 1 wherein the control elements comprise fins.
 3. An aquatic device according to claim 2 wherein each fin comprises a leading end, a trailing end, and upper and lower control surfaces therebetween.
 4. An aquatic device according to claim 3 wherein the upper and lower control surfaces taper inwardly with respect to each other in the direction towards the trailing end.
 5. An aquatic device according to claim 3 wherein the leading end is profiled to facilitate movement through the water.
 6. An aquatic device according to claim 1 wherein the handle means are operably connected to the two control elements whereby the user can manually control movement of the control elements one with respect to the other.
 7. An aquatic device according to claim 1 wherein the control elements are pivotally moveable with respect to each other.
 8. An aquatic device according to claim 7 wherein the control elements are movable about a common pivot axis.
 9. An aquatic device according to claim 8 the common axis is generally transverse to the direction of travel.
 10. An aquatic device according to claim 7 wherein the pivot axis is generally horizontal when the aquatic device is travelling in a generally horizontal straight line direction.
 11. An aquatic device according to claim 1 wherein the handle means comprises two handles each connected to a respective one of the control elements.
 12. An aquatic device according to claim 11 wherein the two control elements are disposed adjacent each other and the two handles are located laterally outwardly thereof.
 13. An aquatic device according to claim 11 wherein the two handles are disposed adjacent each other and the two control elements are located laterally outwardly thereof.
 14. An aquatic device according to claim 11 wherein the relative positions of the handles with respect to the control elements are selectively variable between an arrangement in which the two control elements are disposed adjacent each other and the two handles are located laterally outwardly thereof and an arrangement in which the two handles are disposed adjacent each other and the two control elements located laterally outwardly thereof.
 15. An aquatic device according to claim 11 further comprising an axle, each control element and the respective handle connected thereto being rotatably supported on the axle.
 16. An aquatic device according to claim 16 wherein the control elements and the handles are removable from the axle.
 17. An aquatic device according to claim 1 adapted to be towed through the water.
 18. An aquatic device according to claim 17 further comprising a connection means for attachment to a tow line.
 19. An aquatic device according to claim 18 wherein the connection means is associated with the axle.
 20. An aquatic device according to claim 19 wherein the connection means comprises a bridle having sections extending from each end of the axle.
 21. An aquatic device according to claim 19 wherein the connection means comprises a coupling on the axle, the coupling being so located that there is a respective control element and handle to each side thereof.
 22. An aquatic device according to claim 1 adapted to be propelled through the water by the user.
 23. An aquatic device according to claim 1 further comprising an on-board propulsion system.
 24. An aquatic device for towing a user through a body of water, the aquatic device comprising handle means adapted to be grasped by the user, and two control elements moveable one with respect to the other for directional control of the device.
 25. An aquatic device according to claim 1 wherein each control element is configured to guide water flow with respect to the control surface.
 26. An aquatic device according to claim 25 wherein each control element comprises protrusions extending from either or both of the upper and lower control surfaces.
 27. An aquatic device according to claim 26 wherein the protrusions comprise an outer rib extending between the leading end and the trailing end of each control element.
 28. An aquatic device according to claim 27 wherein the protrusions further comprise an inner rib extending between the leading end and the trailing end of each control element.
 29. An aquatic device according to claim 27 wherein the outer rib is located at an outer side edge of the control element.
 30. An aquatic device according to claim 29 wherein the outer rib is configured to taper inwardly in the forward direction and merge with the leading end of the control element.
 31. An aquatic device according to claim 27 wherein the inner rib is located adjacent an inner side edge of the control element.
 32. An aquatic device comprising handle means adapted to be grasped by a user to apply propulsion thereto, and two control elements moveable one with respect to the other for manoeuvring the aquatic device while being propelled by the user, the handle means being operably connected to the two control elements whereby the user can manually control movement of the control elements one with respect to the other.
 33. A swimming aid comprising handle means adapted to be grasped by a user, and two control elements moveable one with respect to the other to manoeuvre the swimming aid, the handle means being operably connected to the two control elements whereby the user can manually control movement of the control elements one with respect to the other.
 34. An aquatic device comprising handle means adapted to be grasped by a user, and two control elements moveable one with respect to the other to manoeuvre the aquatic device; wherein the control elements comprise water guiding members.
 35. A swimming aid comprising handle means adapted to be grasped by a user, and two control elements moveable one with respect to the other to manoeuvre the aquatic device; wherein the control elements comprise water guiding members. 